Adrenal Insufficiency

Question 1

What is adrenal insufficiency?

Answer 1

Adrenal insufficiency is where the adrenal glands do not produce enough steroid hormones, particularly cortisol and aldosterone. Steroids are essential for life and therefore the condition is life threatening unless the hormones are replaced.

Question 2

What is Addison’s disease?

Answer 2

Addison’s Disease refers to the specific condition where the adrenal glands have been damaged, resulting in a reduction in the secretion of cortisol and aldosterone. This is also called Primary Adrenal Insufficiency. The most common cause is autoimmune.

Question 3

What is secondary adrenal insufficiency?

Answer 3

Secondary Adrenal Insufficiency is a result of inadequate ACTH stimulating the adrenal glands, resulting in low cortisol release. This is the result of loss or damage to the pituitary gland. This can be due to surgery to remove a pituitary tumour, infection, loss of blood flow or radiotherapy.

Question 4

What is Sheehan’s syndrome?

Answer 4

Sheehan’s syndrome is where massive blood loss during childbirth leads to pituitary gland necrosis.

Question 5

What is tertiary adrenal insufficiency?

Answer 5

Tertiary Adrenal Insufficiency is the result of inadequate CRH release by the hypothalamus. This is usually the result of patients being on long term oral steroids (for more than 3 weeks) causing suppression of the hypothalamus. When the exogenous steroids are suddenly withdrawn the hypothalamus does not “wake up” fast enough and endogenous steroids are not adequately produced. Therefore long term steroids should be tapered slowly to allow time for the adrenal axis to regain normal function.

Question 6

What are the symptoms of adrenal insufficiency?

Answer 6

Fatigue
Nausea
Cramps
Abdominal pain
Reduced libido

Question 7

What are the signs of adrenal insufficiency?

Answer 7

• Bronze hyperpigmentation to skin (ACTH stimulates melanocytes to produce melanin)
• Hypotension (particularly postural hypotension)

Question 8

What are the investigations for adrenal insufficiency?

Answer 8

1. Hyponatraemia
2. Hyperkalaemia
3. Early morning cortisol
4. Short synacthen test
5. ACTH
6. Adrenal autoantibodies
7. CT/MRI adrenals
8. MRI pituitary

Question 9

How does the short synacthen test work?

Answer 9

It is ideally performed in the morning when the adrenal glands are most “fresh”. The test involves giving synacthen, which is synthetic ACTH. The blood cortisol is measured at baseline, 30 and 60 minutes after administration. The synthetic ACTH will stimulate healthy adrenal glands to produce cortisol and the cortisol level should at least double. A failure of cortisol to rise (less than double the baseline) indicates primary adrenal insufficiency (Addison’s disease).

Question 10

How does the long synacthen test work?

Answer 10

The long synacthen test is rarely used anymore because we can now measure ACTH levels. It was used to distinguish between primary adrenal insufficiency and adrenal atrophy secondary to prolonged under stimulation in secondary adrenal insufficiency. It involves giving an infusion of ACTH over a long period.

Question 11

How does the long synacthen test help to distinguish between primary adrenal failure and adrenal atrophy?

Answer 11

• In primary adrenal failure there is no cortisol response as the adrenals no longer function.
• In adrenal atrophy (secondary adrenal insufficiency), the prolonged ACTH eventually gets the adrenals going again and cortisol rises.

NB: Now we can simply just measure ACTH and this indicated the underlying cause

Question 12

How can you treat adrenal insufficiency?

Answer 12

Treatment of adrenal insufficiency is with replacement steroids titrated to signs, symptoms and electrolytes.

1. Hydrocortisone is a glucocorticoid hormone and is used to replace cortisol.
2. Fludrocortisone is a mineralocorticoid hormone and is used to replace aldosterone if aldosterone is also insufficient.

Question 13

What should a patient with adrenal insufficiency do when they are ill?

Answer 13

Doses of steroids are doubled during an acute illness until they have recovered to match the normal steroid response to illness.

Question 14

What is an addisonian crisis?

Answer 14

Addisonian crisis is the term used to describe an acute presentation of severe Addisons, where the absence of steroid hormones leads to a life threatening presentation.

Question 15

What is the presentation of an addisonian crisis?

Answer 15

• Reduced consciousness
• Hypotension
• Hypoglycaemia, hyponatraemia and hyperkalaemia
• patients can be very well.

Question 16

When can an addisionian crisis present?

Answer 16

It can be the first presentation of Addisons Disease or triggered by infection, trauma or other acute illness in someone with established Addisons. It can present in someone on long term steroids suddenly withdrawing those steroids.

Question 17

What is the management of an addisonian crisis?

Answer 17

Do not wait to perform investigations as can be life threatening. Start treatment immediately.

• Intensive monitoring if unwell
• Parenteral steroids (IV hydrocortisone 100mg stat then 100mg every 6 hours)
• IV fluid resuscitation
• Correct hypoglycaemia
• Careful monitoring of electrolytes and fluid balance